Prenatal and postnatal differentiation of the small intestine in rat.

UNLABELLED: The gastrointestinal tract in the early prenatal development is an endoblastic mesenchyme-lined tube. The endoblast differentiates and gives origin to all epithelial structures (covering epithelium, glands). The mesenchyme develops into connective tissue, blood vessels, the smooth muscle cells of lamina muscularis mucosae and muscular tunic. Neuroectoblast cells participate in these processes--individual cells with future endocrine function, nerve cells and fibers that form nerve plexuses and vegetative ganglia. AIM OF THE PRESENT STUDY: To trace the changes in the small intestine development during the prenatal period in rat embryos and fetuses, and during the postnatal period in newborn rats. We specifically studied the beta-actin expression in the cytoskeletal structures of the covering epithelium and in the contractile elements of the differentiating smooth muscle cells. The presence and localization of the enteroendocrine EC cell was studied using the immunohistochemical expression of serotonin in them. MATERIAL AND METHODS: Material from rat embryos and fetuses aged 8-11, 12-15, 16-20 days of gestation and small intestine fragments from newborn rats was studied using routine hematoxylin-eosin staining, enzymohistochemically for succinate dehydrogenase and immunohistochemically for beta-actin and serotonin. RESULTS: In the early embryogenesis (8-11 day of gestation), the primitive gut of rat embryos is an endoblastic tube of 2-3 layers of cuboidal cells covered with a thin layer of mesenchyme. In the subsequent stages of embryonic and fetal development the processes of differentiation run at different rates in the different tissues. The maturation process in the small intestine wall of one-day-old newborn rats is incomplete. The mucosa presents with shallow crypts and loosely set villi. Differentiated resorptive and enteroendocrine EC cells are found in the lining epithelium. CONCLUSION: The changes we found in the beta-actin expression in the contractile elements of the differentiating smooth muscle cells and the cytoskeletal structures of the lining epithelium probably reflect the induction interference between the derivatives of the mesenchyme and endoblast.

Somatotypological characteristics of children with type 1 diabetes mellitus.

INTRODUCTION: Human constitutional types are genetically predetermined and remains constant in their basic features. The type could be changed to a certain extent by environmental factors, diseases and some other factors. AIM: To define the somatotype of children with type 1 diabetes mellitus and compare it to the somatotype of healthy children. PATIENTS AND METHODS: An anthropometrical study was performed in 71 boys and 69 girls with type 1 diabetes. The anthropometric measures including weight, height, corrected contracted arm girth, medial calf girth, triceps brachii, subscapular and suprailiac skinfolds, biepicondylar humerus breadth and biepicondylar femur breadth were taken to determine the somatotype. The somatotypes were determined according to Heath-Carter method (1967). The sample was divided into two age groups for both sexes: from 7 to 12 and from 12 to 18 years. One hundred healthy age-matched boys and girls were used as a control sample in the study. RESULTS: The diabetic boys aged 7 - 12 years presented with balanced mesomorph somatotype (endo 2.7-meso 4.8-ecto 2.3), while the healthy boys were with endomorphic mesomorph somatotype (3.4-5.2-2.7). Both the diabetic and healthy boys aged 12-18 years presented with balanced mesomorph somatotype (3.1-4.2-3.5 and 3.4-5.0-3.2, respectively). The somatotype of the diabetic girls aged 7-12 years was balanced mesomorph (3.0-4.2-2.8). The healthy girls of the same age presented with the endomorphic mesomorph (3.7-4.9-2.7). The diabetic girls aged 12-18 years were with mesomorphic endomorph somatotype (4.9-3.7-2.5) and the somatotype of the healthy girls was mesomorph endomorph (4.5-4.1-2.9). CONCLUSION: Mesomorphy was dominant in the diabetic and healthy boys. Mesomorphy was dominant in the diabetic and healthy girls aged 7-12 years. In the 12-18 age group endomorphy increased becoming dominant in the diabetic children and equal to mesomorphy in the healthy ones.